Impact of Early Low-Grade Proteinuria and Allograft Dysfunction on Survival in Expanded Criteria Donor Kidney Transplant Recipients

• The early association of low-grade proteinuria and allograft dysfunction represents an important risk factor for graft loss in ECD KT recipients.
• Strategies to optimize renal function could improve the outcome in this specific population.

IntroductionRecent studies have demonstrated a relationship between low-grade proteinuria and worse graft survival, but this has not been fully studied in expanded criteria donor (ECD) kidney transplant recipients.AimThe aim of this study was to assess whether the combination of early low-grade proteinuria (<1 g/d) and allograft dysfunction at the third month post-transplantation predicts outcomes in terms of survival in ECD kidney transplant recipients.Material and MethodsWe studied a cohort of 269 ECD kidney transplant recipients subdivided into 4 groups according to clinically relevant proteinuria (300 mg/d) and median creatinine (Cr; 1.7 mg/dL; interquartile range, 1.4–2.1 mg/dL) at the third month post-transplantation: Group A (Cr <1.7 mg/dL and proteinuria <300 mg/24 h; n = 97), Group B (Cr <1.7 mg/dL and proteinuria ≥300 mg/24 h; n = 38), Group C (Cr ≥1.7 mg/dL and proteinuria <300 mg/24 h; n = 79), and Group D (Cr ≥1.7 mg/dL and proteinuria ≥300 mg/24 h; n = 55).ResultsDeath-censored graft survival was significantly lower in Group D compared with the rest (P < .007). Multivariate Cox regression analysis using fixed covariates showed that the combination of low-grade proteinuria and a lower estimated glomerular filtration rate (eGFR) as associated with graft failure (hazard rate [HR] 2.5, 95% confidence interval [CI], 1.09–5.97; P = .03).ConclusionsThe early association of low-grade proteinuria and allograft dysfunction represents an important risk factor for graft loss in ECD kidney transplant recipients. Strategies to optimize renal function could improve the outcome in this specific population.